Circuit breaker



T. M. COLE CIRCUIT BREAKER Nov. 7, 1944.

Filed Sept. 26, 1941 ik x lg I02 I06 T [A o 5 IO 5 l6 4 I 3nnentor Tu nns M. Coma CZ ltorneg Patented Nov. 7, 1944 CIRCUIT BREAKER Thomas M. Cole, New York, N. Y., assignor to Cole Electric Products Co. Inc., Long Island, City, N. Y., a corporation of New York Application September 26, 1941, Serial No. 412,356

3 Claims.

This invention relates to electric circuit breakers and, more particularly, to circuit breakers of the type set forth in United States Letters Patent No. 2,242,717 granted upon an application filed by me and Christopher I. Smith.

One object of the invention is the provision in a circuit breaker of the above indicated type of an assembly unit comprising a manuallyactuated operating member and the companion contact members carried by and secured thereto in such manner that these parts can be readily assembled as a unit in the casing of the circuit breaker in association with the other parts thereof.

Another object of this invention is to construct the circuit breaker in such manner that upon disengagement of the companion contact members any are which may be drawn therebetween extends in a direction away from the part of the casing at which the breaker is manually operated. The above and other objects, features and advantages of the invention will be more particularly described in the following specification and pointed out in the claims, and for a more complete understanding thereof reference is to be had to the accompanying illustrative drawing.

In the drawing:

Fig. l-is a side view of the circuit breaker, the

cover of the casing being removed, showing the.

circuit breaker closed;

Fig. 2 is a view similar to Fig. 1 showing the circuit breaker tripped;

Fig. 3 is a view similar to Fig. 1 showing the Fig. 8 is a top plan view of the circuit breaker. I

' member l4, molded or otherwise made of insulation material, is pivotally mounted in the casing, preferably in the manner hereinafter to be detailed. and is provided with an operating knob or handle I! which projects through an opening II in the casing. A contact member 20 is mounted in fixed relation to operating member l4, be-

ing carried by a metal plate or bracket 22 fixed in a recess 24 provided in one side of the body portion 26 of said operating member. Said bracket 22 is fixed in position in said recess in any suitable way as by rivets 28. Bracket 22 is provided with a lateral part 30 to which contact member 29 is secured for positioning said contact member at the same side of the operating member at which the companion contact member 32 and its other end connected to part 35 of arm 34' biases arm 34 for movement to disengage contact member 32 carried by said arm from the companion contact member 20. Thus, both contact members are movable with operating member l4 and said contact members are also relatively movable for engagement with and disengagement from each other.

Contact carrying arm 34 is electrically connected by a fiexible conductor or pigtail 40 to an overload tripping device 42 here shown as a thermostatic device constituted by a bi-metallic strip. The free end of strip 42 releasably engages part 43 of arm 34 thus normally holding said arm against movement in a counter-clockwise direction viewing Figs. 1 to 3. Upon the occurrence of an overload strip 42 is flexed out of engagement with said arm and spring 36 moves arm 34 to circuit-opening position. The fixed end of strip 42 is anchored in position in the casing by being fixed to a terminal member 44 held in position in the. casing by a screw 48 and a companion knurled nut 48 by which one of the terminal wires (not shown) is connected to the circuit breaker. It will be observed that an end portion of easing. I0 is provided with a recess 50 which provides access to the head of screw 46 and with a recess 52 which is open at one side bracket 22 by a flexible conductor or pigtail 00. Terminal member 58 is preferably L-shaped as shown and is held in a corresponding recess 82 formed in casing I0, said recess being open at the side of the casing at which cover I2 is positioned. Said terminal member is provided with a terminal wire binding screw Q4 for the other terminal wire (not shown).

As indicated above an important feature of the present invention is the assembly of the contact members and spring 36 as a unit with the operating member I4. In this respect the construction and arrangement is such that the contact members are both carried by the movable operating member I4 and are secured in assembled relation therewith together with the spring 36 so that these parts can be mounted in assembled relation as a unit in the casing by merely placing the assembly unit in position in the casing. The manner in which this is accomplished will now be described somewhat in detail, although it will be understood that the present specific construction while preferred may be departed from and altered as will readily occur, in view of the present disclosure, to those skilled in the art. By reference to Fig. 4 it will be observed that the body portion 26 of operating member id is provided with an axial opening 66 therethrough and with an integral cylindrical axial boss 88 which projects laterally from one side of said operating member. Said axial opening 66 extending through said boss and the latter is provided with a recess I which registers with said opening. A cylindrical metal pin I2 extends through opening 66 and has a head or part I4 of enlarged diameter at one end thereof. The other end I6 of pin I2 is located in recess I0 oi boss 68 and is upset and thereby enlarged and engaged with the shoulder I8 formed internally oi said boss at said recess I0. Pin I2 preferably has a forced fit in opening 66 and is thereby fixed axially of body portion 26 of operating member I4. Boss 68 is received in a bearing opening 80 in the adjacent wall-82 oi casing in and head I4 is received in a bearing opening 84 in casing cover I2, which constitutes the opposite parallel wall of the casing, whereby operating member I4 is mounted for pivotal movement. The contact carrying arm 34 is pivotallv mounted on pin I2 between head I4 oi the latter and the adjacent side of the body portion 26 of operating member I4 whereby said contact carrying arm 34 is carried by said operating member and is also pivotally mounted thereon. Arm 24 is thus held against movement axially of member I4 and the contact member 32 carried by said arm is maintained in registry with companion contact mem.- ber 20. As stated above, spring 34 is connected to part 35 of arm 24 and to the body portion 28 of operating member I 0, one end of said sprins being engaged in notch 38 in said operating member.

It will be understood that when bi-metallic strip 42 engages the adjacent end or contact carrying arm 24, the circuit breaker can be manually opened and closed by turning operating member I4 from the closed position shown in Fig. 1 in which the companion contact members and 32 are engaged with each other to the open position shown in Fig. 3 in which said companion contact members are disengaged from each other. It will be understood also that, as described above, when the switch is closed and an overload occurs the bi-metallic strip 42 is deflected so that the end thereof which normally engages the adiacent end or contact carrying arm 24 is flexed out of said engagement thus releasing said arm for movement to disengage the contact member 22 carried thereby from the companion contact member 20, said movement being eflfected by spring 36. Strip 42 flexes, upon an overload, in a direction transversely of the plane of movement of contact carrying arm 34 and, more speciflcally, toward cover I2 of the casing. The circuit breaker in the tripped condition thereof is illustrated in Fig. 2. The movement of arm 24 in switch-opening direction by spring 36 is limited by the engagement of part 35 of said arm with a shoulder 88 formed on the body portion 28 of operating member I4. It will be noted that when the switch is tripped knob I6 moves from the position illustrated in Fig. l to the position illustrated in Fig. 2, in which position said knob engages a stop 90 formed incaslng I0. An edge portion of operating member I4 is provided with a red or other mark or trip indicator 92 which is exposed to view through opening I8 in the casing when the switch is tripped, thus to indicate the tripped condition of the switch, said indicator being concealed in the normal open or normal closed condition of the breaker. Also, as here shown, the casing is preferably provided with legends closed and open at opposite ends, respectively, of opening I B to indicate the corresponding condition of the switch by reason or the position of the handle I6 adjacent said ends, respectively, of opening I8, except that when indicater 92 is exposed to view. the tripped condition is indicated as stated.

The circuit breaker is preferably provided with means for the manual operation of the switch with a snap action. For this purpose an overcentering spring 94 is provided. Said spring comprises, as here shown, a. part 98 which engages the body portion of operating member I4 in a notch 08. Said part 06 is integral with arms 91 and 08 provided with coils I00 and I02, the ends of said coils being integral with arms I 04 and I06, respectively, terminating in inturned confronting end portions I08 and H0 which engage an adjacent wall portion 0! casing I0 in a notch II2 formed therein. It will be noted that spring 94 is V-shaped, coils I00 and I02 being located at the apex of the V and parts 96 and I00, Ill being located at the free ends of the V. By reference to Figs. 1, 2 and 3 of the drawing it will be clearly understood that upon the manual operation of operating member I4 overcentering spring 04 is eflective to impart to said operating member a snap action in the opening and closing movements oi the circuit breaker in the manual operation thereof. Also, it will be observed that spring 94 assists in tripping the break. er as it moves operating member I4 from the position shown in Fig. 1 to the position shown in Fig. 2, when strip 42 disengages arm 24.

It will be noted that, as indicated above, contact members 20 and 32 are so positioned in the casing in respect to each other and have such relative movement that upon the tripping oi the circuit breaker any are which might be formed is directed away from the opening II through which the manually operated part or the breaker extends, thus to prevent arcing near knob II on the passage of an arc through said opening. It will be noted that contact members 20 and I2 disengage at a point remote from the opening II at which knob II is positioned. Also, as here shown, an arc chute H4 is provided in casing II in the region of separation of contact members 20 and 22. Said arc chute being provided with same.

an opening I It for the passage or gases out of the casing. As shown, said are chute lllis constructed to provide a tortuous passage for cooling the arc whereby to more rapidly extinguish the It will be understood that said are chute is effective to extinguish the are formed not only when the switch is tripped under the control of the overload device but also when the switch is breaker trips open, it is reset by moving knob l6 of operating member M from the position shown in Fig. 2 to the position shown in Fig. 3, thus to permit strip 42 to engage arm 34, provided of course that strip has in the meantime cooled suificiently, and then the breaker is closed by moving knob it from the position shown in Fig. 3 to the position shown in Fig. 1. In this movement of the operating member 14 to close the breaker, arm 34 is' held against movement by strip 42 and spring 36 is stressed and thereby conditioned to open the breaker when strip 42 is flexed by an overload and releases sa d arm.

The manner of assembling the parts of the circuit breaker in casing I is considered more or less obvious in view of the above description. It will be understood that the assembly unit consisting of the member I4, contact members 20 and 32, and spring 38 is made before it is placed in casing ID, the parts being secured in position on member [4 by pin 12. Also, the pigtails which connect terminal members, strip 42 and terminal member 58 to arm 34 andplate 22 are secured. preferably by welding, before placing the unit in position in the casing. Said unit spring 94. terminal members 44 and 58, and strip 42 are all placed in position in the casing through the open side thereof, cover l2 being removed, and finally said cover is secured in position.

While I have shown and described the preferred embodiment 01' my invention, it will be understood that the latter may be embodied otherwise than as herein specifically shown or described, and further it will be understood that in the illustrated embodiment certain changes in the details 01' construction and in the arrangement of parts may be made and that certain parts may be omitted. Accordingly, I do not wish to be limited to the specific construction herein shown or described except to the extent which may be required by the scope of the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. In an electric circuit breaker, a casing, relatively movable contact members positioned in said casing and engageable with and disengageabie from each other within said casing, an operating member for engaging and disengaging being mounted for movement in said casing, an arm carried by said operating member, one of said contact members being fixed to said operating member for movement therewith and the other of said contact members being carried by said arm, said arm being mounted on said operating member fo movement therewith under one condition and for movement in relation thereto under another condition, current responsive means for holding said contact members releasably in engagement with each other, means operable under the control of said current responsive means fOr effecting said relative movement of said other contact member for disengaging the same from said one of the contact members, and means carried by said operating member engageable with said casing for mounting said operating member for said movement thereof, said last means comprising a recessed cylindrical axial projection in fixed relation to said operating member at one side thereof and a pin passing through said member axially of said projection and having one end secured in the recess of said projection, the other end of said pin having a cylindrical part disposed at the other side 01' said operating member, said casing having bearing recesses in which said cylindrical projection and said cylindrical part are movably supported.

2. In an electric circuit breaker, the sub-combination comprising an operating member adapted to. be mounted for pivotal movement, a contact member carried by said operating member in fixed relation thereto, said operating member having an axial opening, a pin passing said contact members, said operating member through said opening axially of said operating member, an arm pivotally mounted on said pin at one side 01' aid operating member and held against axial movement by a part of said pin and.

the adjacent side of said operating member, the other side of said operating member engaging an adjacent part of said pin for preventing axial movement of the latter, and a contact member carried by said am and movable by the latter into and out oi. engagement with said first mentioned contact member.

3. In an electric circuit breaker, the subcombination comprising an operating member adapted to be mounted for pivotal movement, a contact member carried by said operating member in flxed relation thereto, said operating member having an axial opening, a pin passing through said opening axially of said operatin member, an arm pivotally mounted on said pin at one ide of said operating member and held against axial movement by a part of said pin and the adjacent side of said operating member, the other side oi. said operating member having a cylindrical part projecting therefrom axially thereof and provided with a recess in registry with said opening, said pin having a part thereoi secured in said recess for preventing axial movement of said pin, and a contact member carried by said arm and movable by the latter into and out 01' engagement with said first mentioned contact member.

THOMAS M. COLE. 

